Process of treating spent grain.



JAMES A. TILDEN, OF HYDE PARK, MASSACHUSETTS, ASSIGNOR TO HERSEYMANUFACTURING COMPANY, OF SOUTH BOSTON, MASSACHUSETTS.

PROCESS OF TREATING SPENT GRAIN.

SPECIFICATION forming part of Letters Patent No. 67 9,065, dated July23, 1901.

Application filed January 22, 1898. Serial No. 667,632. (No specimens.)

T al whom i may C I may state at the outset that in carrying Be it knownthat I, JAMES A. TILDEN, acitiout my process any desired apparatuscapazen of the United States, residing at Hyde bio of carrying on themode of operation set Park, in the county of Norfolk and State of forthmay be used, my present invention be- 55 Massachusetts, have invented anew and useing independent of any particular machinery ful Improvementin Processes of Treating or apparatus, as the steps of the process canSpent Grain, of which the followingis a specibe carried out in many andvarious ways, as

fication. will be clearly understood by those skilled in My inventionrelates to an improved procthe art. 10 ess of treating spent grainssuch,for ex- I will illustrate the process by describingit ample, as arecommonly known as brewers in connection with brewers grains, and I willgrains or distillers slops; and it has for assume, for instance, thatthe grains as reits object to provide a simple and economic ceived fortreatment contain, for example, process of treating such grains in sucha maneighty per cent. of water. The first step of the 65 ner that theyshall retain their nutritive process consists in drainingthe mass ofgrains qualities to the highest degree; and to these to remove a certainpercentage of the water,

ends my invention consists in a process inwhich will pass off in theform of practically volving the steps or mode of operation subclearwater Without carrying with it the nustantially as hereinafter moreparticularly tritive portions of the grain, and in this way 70 setforth. I find that twenty-five per cent. of the water It is well knownthat spent grainssuch, of the mass may be removed without detriforexample, as brewers grainscontain a ment by what maybe termed gravityfiltraconsiderable amount of valuable nutritive tion. Broadly speaking,no special filtering materials, and various ways of treating theapparatus is necessary in carrying out this 75 z 5 material to preservethese qualities have been step of the process, as the wet grains may besuggested. These spent grains as they come simply piled on the floor andthe water will from breweries and similar places contain drain andfilter through the mass, or, what is large amounts of water, rangingfrom sevpreferable, the wet grains may be delivered enty-five to evenninety per cent. of the toto a suitable filtering-receptacle, where the80 3o tal weight of the wet grains. I-Ieretofore two free Water willgradually filter down through general systems of treating the grainshave the grains and pass oft as practically clear been used, in one ofwhich the entire amount water. The next step of the method consists ofthe water contained in the mass of wet in subjecting the mass of grainsto pressure grains has been evaporated by the applica to squeeze out alarge proportion of the water 85 tion of heat; but the objection to thissysand to leave the grains in a relatively dry tem is found in theexpense attending the condition, and I find that by pressure fiftyevaporation of so large an amount of water. per cent. and upward of theoriginal water can In another system a portion of the water has beeasily removed from the mass; but in its been expelled by pressing thespent grains removal more or less of the valuable nutritive o and theremainder evaporated, and the obqualities of the grains pass off withthe exjection to this system lies in the fact that in pressed water, andhas consequently been a the pressing of the grains a certain amountwaste of the material. The mass maybe of valuable nutritive qualities ofthe grains pressed in any suitable way, and any suitable is wasted,passing off in the water pressed apparatus adapted to the purpose can beused 95 from'the mass of the grains. in carrying out this step of theprocess.

In my improved process I am able to re- One of the distinguishing andperhaps the duce the cost of drying the grains and at the essentialfeature of my process relates to the same time retain the nutritiveportions of the saving of the nutritive portions of the grains grains,and I will now proceed to describe carriedoff in thewaterpressed fromthe mass, 10:

the various steps or method of operation in and in order to do thisIreturn the expressed carrying out my process. liquid to the mass of wetgrains being treated by the first step of the process, and I find thatthe valuable nutritive portions ordinarily carried off by the wastewater from the pressed material are thus restored to the grains,apparently being absorbed or retained by the husks or cellular tissue ofthe grains, so that the material loses none of its valuable qualities,and the excess of water may be filtered off, as set forth in the firststep of the process. This expressed liquid may be restored to thefiltering mass by any suitable means, as by hand, or pumps, by gravity,or otherwise, depending upon the character and arrangement of theapparatus by which my process is carried out. The mass of material afterbeing pressed may, if desired, be subjected to heat or dry air toevaporate or dry out any Water remaining in the mass, and this may beaccomplished in any suitable way or apparatus.

By this process I am enabled to eliminate the water from the grainswithout going to the expense of evaporating the entire amount by theapplication of heat, and I avoid the loss of the nutritive portions ofthe grains due to the pressing thereof and provide a practicallycontinuous, rapid, and inexpensive process of treating spent grains.

The advantages of my process may be more apparent by a comparison withthe ordinary systems. Starting, for instance, with a thousand pounds ofwet grains, eight hundred pounds of which is water, for example, if thiswater was driven off entirely by heat it would involve a relativelylarge expense. If a large proportion of the water was driven 0ft bypressure and the expressed water wasted, the expense of removing thewater would be reduced, but a large amount of the valuable properties ofthe grains would be lost. By

my process I first remove a certain portion of the excess of water bydrainage and filtration, the water passing ofi as clear liquid, and Imay say, for example, that two hundred pounds of the water are thusremoved. I then subject the mass to pressure, removing, for example,four hundred pounds of the water, and as this water contains much of thenutritive properties of the grains it is restored to the mass beingfiltered, the nutritive portions being absorbed or retained by the husksor cellular tissue of the grains. The remaining two hundred pounds ofwater in the mass may then be evaporated by heat at relatively littleexpense. It will thus be seen that instead of evaporating the whole ofthe water by heat only a relatively small proportion of thewater is soremoved, the bulk of the water being removed by pressure and at the sametime the valuable nutritive qualities being saved, so that the resultantproduct is superior and produced at a less expense than by the oldprocesses.

What I claim is-- 1. The process substantially as hereinbefore set forthof treating spent grains, which consists in removing a,portion of theliquid from the mass of material by gravity filtra tion, subjecting themass of material from which the liquid has thus been filtered topressure to express a large proportion of the liquid, and returning theexpressed liquid to the unpressed mass of material.

'2. The process substantially as hereinbefore set forth of treatingspent grains, which consists in removing a portion of the liquid fromthe mass of material by gravity filtration, subjecting the mass ofmaterial from which the liquid has been filtered to pressure to expressa large portion of the liquid, returning the expressed liquid to theimpressed mass of material and subjecting the compressed mass to heat toevaporate the remaining liquid.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES A. TILDEN:

